剑桥雅思4,test 1,reading 1里有句句子实在疑惑.就是那篇孩子对热带雨林的错误理解的那篇It seems schools may not be providing an opportunity for children to re-express their ideas and so have them tested and refined by teachers and their peers.1. may not be providing, provide为什么要+ing?属于什么时态?be后面不是应该是被动态吗?2. have them tested,应该是现在完成时吧,为什么have放在them的前面?望指教,谢谢.

剑桥雅思4,test 1,reading 1里有句句子实在疑惑.
就是那篇孩子对热带雨林的错误理解的那篇
It seems schools may not be providing an opportunity for children to re-express their ideas and so have them tested and refined by teachers and their peers.
1. may not be providing, provide为什么要+ing?属于什么时态?be后面不是应该是被动态吗?
2. have them tested,应该是现在完成时吧,为什么have放在them的前面?
望指教,谢谢.